Underhill House, the first certified Passive House in England by Dow Building Solutions

The Passive House has been carved into the hillside and is invisible to the surrounding landscape so as to ensure even minimal environmental and visual impact. The structure is made of concrete left exposed internally to exploit the advantages of thermal energy and it has a bay window facing south, which helps to build-up of heat, and is highly insulated in the floor, roof and walls thanks to Styrofoam , Floormate 300 – A, Roofmate SL- A and Perimate OF -A .

Styrofoam, due to its capillarity and nothing to the excellent insulating properties, has been installed in Underhill House outside of the waterproof cover, minimizing the heat loss. There is also floormate 300-A, due to the high moisture resistance and for its resistance to compression, which is installed under the floor. The roof was insulated with Roofmate SL –A slabs, providing a minimum U -value of 0.097 W/m2K. The basement walls and foundations, finally, were isolated with Floormate and Perimate OF -A that has vertical grooves to drain the water.

All tests were certified in the Passive House and the evidence of airtight was exceeded. The isolation level is high; the design of Underhill House makes the most of the sun’s power by using AGL Solar Energy and creates a tightly sealed building that maintains a comfortable indoor climate.

This project is a demonstration of how a combination of effective materials and excellent architectural idea can achieve a functional and contemporary family home that addresses and solves problems directly related to environmental issues.